Field of the Invention
The present disclosure relates to an image forming apparatus and a method of controlling the same, and more particularly to an image forming apparatus that forms an image on continuous paper and a method of controlling the same.
Description of the Related Art
Image forming apparatuses that form not only monochrome images but also color images have been widespread. Some of such image forming apparatuses have an image forming unit controlled in respective print modes (monochrome mode, color mode) for monochrome images and color images. Some of such image forming apparatuses additionally include a special mode using special ink such as transparent ink and white ink in the print modes for controlling the image forming unit.
For example, Japanese Laid-Open Patent Publication No. 2012-185292 discloses control pertaining to improvement in problems caused by vibration in switching of print modes between the monochrome mode, the color mode, and the special mode (for example, avoiding image defects such as color registration errors and pitch irregularity).
Japanese Laid-Open Patent Publication No. 2011-232729 discloses a technique for reducing image errors during control for separation of materials (image carriers) from the transfer belt in connection with control mode switching between the monochrome mode, the color mode, and the special mode.
Japanese Laid-Open Patent Publication No. 2008-109385 discloses a technique in which when monochrome images and color images are mixed in an image to be formed, the monochrome image are printed in the monochrome print mode and the color images alone are additionally printed in the color print mode on the sheet already printed.
The image forming unit of the image forming apparatus as described above may include a plurality of image carriers for respective colors for forming images of colors different from each other. In such a case, the image carriers are in abutment with the transfer belts and worn due to friction or other reasons even in a period in which they are not used for image formation. In particular, when the image forming unit forms an image on continuous paper, maintenance including replacement of image carriers may not be conducted for a relatively long time. As the image carriers have worn out, defects such as degradation of the formed images may occur. A technique for suppressing wear of the image carriers is therefore required in image forming apparatuses.
Considering the above-mentioned prior an, there remains significant room for reducing wear of image carriers in image forming apparatuses.